The present invention relates to a disk drive system provided with a latching mechanism for holding an actuator in a parking position against an external shock.
In a disk drive system, especially the disk drive system arranged in a portable personal computer such as of notebook size, higher reliability is now required with respect to a shock during non-operation.
When a slider mounted on an actuator is moved from a parking position to a data area on a surface of a disk by the shock during non-operation of the disk drive system, the slider is attached to or harms a surface of the data area, which causes a fatal fault.
An actuator locking mechanism is known as a mechanism for holding the actuator in the parking position during non-operation and preventing the actuator from being oscillated and moved to the surface of the data area by the shock.
Considered in a recent disk drive system is a loading/unloading mechanism of the slider for the purpose of preventing the slider from being attached to a surface of the shunting area and of obtaining higher reliability with respect to the above described shock. The loading/unloading mechanism is such that the actuator is held by a component called a ramp provided near an outer periphery of the disk during non-operation of the disk drive system to thereby shunt the slider so as not to make contact with the surface of the disk.
One of the actuator locking mechanisms uses an inertial latching mechanism. In the actuator locking mechanisms using the inertial latching mechanism, the above described ramp of the loading/unloading mechanism or a magnetic locking mechanism or the like is usually used together as an actuator holding mechanism.
The inertial latching mechanism operates when the shock is applied on the disk drive system and latches the actuator by utilizing a force of inertia produced by the shock. This inertial latching mechanism can latch the actuator against a strong shock which cannot be dealt with only by the above described magnetic locking mechanism. The above described actuator holding mechanism holds the actuator when a slight shock is applied against which the inertial latching mechanism does not operate and increases reliability of the actuator locking mechanism.
An example of such an actuator locking mechanism using the inertial latching mechanism is shown in FIGS. 17 and 18. This actuator locking mechanism uses the ramp of the loading/unloading mechanism as the actuator holding mechanism.
In the inertial latching mechanism shown in FIG. 17, when the shock is applied such that an actuator 22 is counterclockwise oscillated (toward a disk 1), a latch lever 101 is oscillated counterclockwise around an oscillatory axis by a force of inertia and an engaging projection 102 abuts against a tip 26c of a coil arm of the actuator 22 to latch the actuator 22.
The inertial latching mechanism shown in FIG. 18 uses two balls 202, which push a latch lever 201 with the force of inertia, and the latch lever 201 latches the actuator 22 around the oscillatory axis (National Publication International Patent Application No. 1997-503608 specification).
An another example of the actuator locking mechanism using the inertial latching mechanism is provided with the inertial latching mechanism shown in FIG. 17 and a magnetic or electromagnetic locking mechanism for magnetically or electromagnetically latching the actuator as the actuator holding mechanism (Japanese Patent Laid-Open No. 8-339645 specification).
A component such as the actuator oscillatably provided on the oscillatory axis is generally accelerated linearly and angularly by the external shock. A force by linear acceleration (a translational force) is applied on a mass center of gravity and a force by angular acceleration (a couple of force) is applied mainly on the oscillatory axis. In a circle around the oscillatory axis which passes the mass center of gravity, a tangential component on the mass center of gravity of the circle is regarded as an effective component and a normal component of the mass center of gravity as an ineffective component. Involved in the oscillation of the above described component is the effective components of the angular and linear acceleration.
When a large shock is applied such that the actuator 22 shown in FIGS. 17 and 18 is clockwise oscillated (apart from the disk 1), however, the actuator bumps against a crush stop (elastic body) 5 and is likely to be moved toward the disk 1 by rebound therefrom.
Namely, in the actuator locking mechanism and the inertial latching mechanism shown in FIG. 17, when the shock is applied such that the actuator 22 is clockwise oscillated (toward the crush stop 5), the inertial latching mechanism does not operate and cannot latch the actuator 22 reversely oscillated.
In the inertial latching mechanism shown in FIG. 18 which operates with the two balls even when the shock is applied in either direction, it is necessary to enlarge mass of the balls or to reduce moment of inertia of the latch lever in order to assure the operation. There is a limit in reducing the moment of inertia of the latch lever, and the enlargement of the mass of the balls makes it difficult to arrange the inertial latching mechanism in a thin-model disk drive system.
The present invention solves such conventional problems and has its object to provide a disk drive system provided with an inertial latching mechanism which has high reliability and can be arranged in a thin-model disk drive system.
In order to achieve the above object, a disk drive system according to aspect 1 of the present invention comprises: an actuator having a head arm mounted with a slider having a head element for recording data in a disk recording medium and reading the recorded data, unloading the head arm to a parking position and loading the head arm from the parking position such that the slider comes close to a surface of the disk recording medium; an inertial arm rotatably supported, engaging the actuator when the head arm is in or near the parking position and releasing the engagement with the actuator when the head arm is in or near a position close to the disk recording medium; and energizing means for holding a position of the inertial arm in a position where the engagement with the actuator is released. Even if a rotational shock is externally applied when the actuator remains in the parking position, moment of rotation is applied on each of the actuator and inertial arm in the same direction and the actuator and inertial arm mutually restrain their operations at an engaging part. Accordingly, oscillation of the actuator to a data area can be avoided. Further, when loading, the position of the inertial arm is held by the energizing means in the position where the engagement with the actuator is released, and the release of the engagement and mode of operation of the engagement between the actuator and inertial arm when loading/unloading can be surely achieved.
In the disk drive system according to aspect 2 of the present invention, the actuator and the inertial arm in aspect 1 have balanced mass with respect to respective centers of rotation.
In the disk drive system according to aspect 3 of the present invention, a ratio of inertia of the actuator and the inertial arm in aspect 1 is equal to a ratio of a distance from the center of rotation of the actuator to an engaging part and a distance from the center of rotation of the inertial arm to the engaging part.
A disk drive system according to aspect 4 of the present invention comprises: an actuator having a head arm mounted with a slider having a head element for recording data in a disk recording medium and reading the recorded data, unloading the head arm to a parking position and loading the head arm from the parking position such that the slider comes close to a surface of the disk recording medium; an inertial arm rotatably supported, engaging the actuator when the head arm is in or near the parking position, releasing the engagement with the actuator when the head arm is in or near the position close to the disk recording medium and having a wind receiver for receiving a force of air flow produced by rotation of the disk recording medium. Even if a rotational shock is externally applied when the actuator remains in the parking position, moment of rotation is applied on each of the actuator and inertial arm in the same direction and the actuator and inertial arm mutually restrain their operations at an engaging part. Accordingly, oscillation of the actuator to a data area can be avoided. Further, when loading, the wind receiver receives the force of air flow produced by the rotation of the disk recording medium so that the force is always applied on the inertial arm in a direction of releasing the engagement with the actuator. Therefore, the position of the inertia arm is held without the energizing means according to aspect 1, and the release of the engagement and mode of operation of the engagement between the actuator and inertial arm when loading/unloading can be surely achieved.
In the disk drive system according to aspect 5 of the present invention, the actuator and the inertial arm in aspect 4 have balanced mass with respect to respective centers of rotation.
In the disk drive system according to aspect 6 of the present invention, a ratio of inertia of the actuator and the inertial arm in aspect 4 is equal to a ratio of a distance from the center of rotation of the actuator to an engaging part and a distance from the center of rotation of the inertial arm to the engaging part.
A disk drive system according to aspect 7 of the present invention comprises: an actuator having a head arm mounted with a slider having a head element for recording data in a disk recording medium and reading the recorded data, unloading the head arm to a parking position and loading the head arm from the parking position such that the slider comes close to a surface of the disk recording medium; an inertial arm rotatably supported, engaging the actuator when the head arm is in or near the parking position and releasing engagement with the actuator when the head arm is in or near the position close to the disk recording medium; first holding means for holding a position of the inertial arm in a position where engagement with the actuator is released; and second holding means for holding the actuator or inertial arm in the parking position. Providing the second holding means for holding the actuator or inertial arm permits always holding the position of the actuator against a slight shock which occurs in the parking position. Namely, oscillation of the actuator to a data area can be avoided even when the slight shock is applied against which the inertial arm does not operate.
More specifically, even if a rotational shock is externally applied when the actuator remains in the parking position, moment of rotation is applied on each of the actuator and inertial arm in the same direction and the actuator and inertial arm mutually restrain their operations at an engaging part. Further, when loading, the position of the inertia arm is held by the first holding means with the engagement between the actuator and inertial arm remaining released. Moreover, when the actuator remains in the parking position, the position of the actuator is held by the second holding means.
In the disk drive system according to aspect 8 of the present invention, the actuator and the inertial arm in aspect 7 have balanced mass with respect to respective centers of rotation.
In the disk drive system according to aspect 9 of the present invention, a ratio of the inertia of the actuator and the inertial arm in aspect 7 is equal to a ratio of a distance from the center of rotation of the actuator to an engaging part and a distance from the center of rotation of the inertial arm to the engaging part.
A disk drive system according to aspect 10 of the present invention comprises: an actuator having a head arm mounted with a slider having a head element for recording data in a disk recording medium and reading the recorded data, unloading the head arm to a parking position and loading the head arm from the parking position such that the slider comes close to a surface of the disk recording medium; an inertial arm rotatably supported, engaging the actuator when the head arm is in or near the parking position and releasing engagement with the actuator when the head arm is in or near the position close to the disk recording medium; and first holding means for holding a position of the inertial arm in a position where the engagement with the actuator is released, and in the parking position, a line connecting the center of rotation and a mass center of gravity of the actuator makes an acute angle with a line connecting the center of rotation and a mass center of gravity of the inertial arm, which can substantially equalize a direction of moment of rotation by linear acceleration applied on each of the actuator and inertial arm. Accordingly, not only a rotational shock but also the operation of the actuator relative to the linear acceleration applied on the mass center of gravity can be restrained, and even if the rotational shock is applied when the actuator remains in the parking position, the moment of rotation is applied on each of the actuator and inertial arm in the same direction. Further, even if a linear shock is applied on the mass center of gravity, the moment of rotation applied on each of the actuator and inertial arm has substantially the same direction. Therefore, the actuator and inertial arm mutually restrain their operations at an engaging part against any shock and oscillation of the actuator to the data area can be avoided.
In the disk drive system according to aspect 11 of the present invention, a ratio of the inertia of the actuator and the inertial arm in aspect 10 is equal to a ratio of a distance from the center of rotation of the actuator to an engaging part and a distance from the center of rotation of the inertial arm to the engaging part.
A disk drive system according to aspect 12 of the present invention comprises: an actuator having a head arm mounted with a slider having a head element for recording data in a disk recording medium and reading the recorded data, unloading the head arm to a parking position and loading the head arm from the parking position such that the slider comes close to a surface of the disk recording medium; an inertial arm rotatably supported, engaging the actuator when the head arm is in or near the parking position and releasing engagement with the actuator when the head arm is in or near a position close to the disk recording medium; first holding means for holding a position of the inertial arm in the position where the engagement with the actuator is released; and second holding means for holding the actuator or inertial arm in the parking position, and in the parking position, a line connecting a center of rotation and a mass center of gravity of the actuator makes an acute angle with a line connecting a center of rotation and a mass center of gravity of the inertial arm, and oscillation of the actuator to the data area can be avoided with respect to both of a slight rotational shock against which the inertial arm does not operate and a linear shock.
More specifically, even if the rotational shock is applied when the actuator remains in the parking position, moment of rotation is applied on each of the actuator and inertial arm in the same direction. Even if the linear shock is applied on the mass center of gravity, the moment of rotation applied on each of the actuator and inertial arm has substantially the same direction. Therefore, the actuator and inertial arm mutually restrain their operations at an engaging part against any shock. Further, when loading, the position of the inertia arm is held by the first holding means with the engagement between the actuator and inertial arm remaining released. Moreover, even if the slight rotational shock is externally applied when the actuator remains in the parking position, the position of the actuator is held by the second holding means.
In the disk drive system according to aspect 13 of the present invention, a ratio of the inertia of the actuator and the inertial arm in aspect 12 is equal to a ratio of a distance from the center of rotation of the actuator to an engaging part and a distance from the center of rotation of the inertial arm to the engaging part.